Jami` at-Tirmidhi, Volume 6, Book 44, Hadith 3359 (DarusSalam) ⓘ

Anas narrated [regarding Allah, Most High’s saying] ‘Verily We have granted you Al-Kauthar’ (108: 1) that the Prophet said: “It is a river in Paradise.” He said: “The Prophet said: ‘I saw a river in Paradise, whose banks had tents were made of pearl. I said: “What is this O Jibril?’” He said: “This is Al-Kauthar which Allah has granted you.”

حَدَّثَنَا عَبْدُ بْنُ حُمَيْدٍ، حَدَّثَنَا عَبْدُ الرَّزَّاقِ، عَنْ مَعْمَرٍ، عَنْ قَتَادَةَ، عَنْ أَنَسٍ ‏:‏ ‏(‏ إناَّ، أَعْطَيْنَاكَ الْكَوْثَرَ ‏)‏ أَنَّ النَّبِيَّ صلى الله عليه وسلم قَالَ ‏"‏ هُوَ نَهْرٌ فِي الْجَنَّةِ ‏"‏ ‏.‏ قَالَ فَقَالَ النَّبِيُّ صلى الله عليه وسلم ‏"‏ رَأَيْتُ نَهْرًا فِي الْجَنَّةِ حَافَتَاهُ قِبَابُ اللُّؤْلُؤِ قُلْتُ مَا هَذَا يَا جِبْرِيلُ قَالَ هَذَا الْكَوْثَرُ الَّذِي قَدْ أَعْطَاكَهُ اللَّهُ ‏"‏ ‏.‏ قَالَ أَبُو عِيسَى هَذَا حَدِيثٌ حَسَنٌ صَحِيحٌ ‏.‏